Our new Blue Boar Dual Arbor Set includes both a 5/8"-18 2-Pin hole saw arbor, and a special adapter that quickly converts it to a 1/2"-20 arbor for small diameter hole saws. The Dual Arbor takes no more space than a single hole saw arbor and is more convenient to carry around in a tool pouch, hole saw kit, or store in a power drill's case.

We took this unique approach as 90% of the time people want to use the 2-Pin type for hole saws that are 1-1/4" or larger in diameter. The 2-Pin mechanism makes it much easier and faster to remove the hole saw after use. Other manufacturers provide a screw on adapter to change a No-Pin 1/2" hole saw arbor to a No-Pin 5/8" hole saw arbor and the advantages of the 2-Pin design are lost.

Note: Hole saws 1-1/4" and larger in diameter are designed to mount on a 5/8"-18 thread arbor or mandrel, and have 2 or more holes for the arbor's 2-Pin mechanism. Smaller diameter (5/8" to 1-3/16") hole saws have a 1/2"-20 thread mount and there not room for holes for the 2-Pin arbor.